I came across this nice quote attributed to Confucius. I do like it, i do not agree 100% with it though.
Great man is hard on himself; Small man is hard on others– Confucius
A great man, refers to someone who possesses qualities such as integrity, self-discipline, and a commitment to personal growth. This person sets high standards for themselves and holds themselves accountable for their actions and decisions. They are self-reflective and continually strive for self-improvement. When they make mistakes or face challenges, they take responsibility and work to learn from them.
On the other hand, a small man refers to someone who lacks these aforementioned qualities. They may be self-centred, lacking in self-awareness, and more inclined to criticize and blame others rather than examining their own actions. They are often quick to judge and find fault in others, using criticism as a means to deflect attention from their own shortcomings.
I think there is more to this than the simplification presented by Confucius.
In reality, people can switch from one status to the other. A person used to finding fault in everyone except himself, can change to start assuming these faults. Vice-versa can also take place, a man committed to high standards, can find himself in a position that forces him to be dependant on others, which would transform this commitment to high standard into a dissatisfaction of the actions of others.